1. Technical Field
This invention relates in general to processing devices and, more particularly, to networks for processing devices.
2. Description of the Related Art
Electronic calculators have evolved significantly since their inception as a general consumer product in the early 1970""s. In addition to arithmetic calculations, current day calculators often provide programming and graphing functions. Graphing calculators include a screen which is able to display graphics in addition to alphanumeric characters.
For some time, graphing calculators have been able to communicate to one another through a wired connection. An example of a calculator of this type is the TI-92 calculator produced by Texas Instruments Incorporated of Dallas, Tex. Wired connections may be used, for example, in a classroom setting where problem sets are downloaded from the teacher""s calculator to the students"" calculators. Once downloaded, the students can use their calculators to solve the problem.
One problem with use of the networked calculators is the lack of control over the communication between students. In some instances, such as when a test is being administered via the network, any communications between students is a problem. On the other hand, it is desirable in other situations to allow student to study in workgroups.
Heretofore, networking schemes for calculators and other processing devices have not supported such flexibility. In some networks, all communication must pass through a master, which controls the communications between calculators. This structure is appropriate for the classroom, but does not provide for communication in other settings, such as the library, where the master is not present. The alternative is a peer relationship where communication is not controlled by a master. This structure fails in the classroom setting where the teacher may wish to restrict communications, for example, during testing.
Therefore, a need has arisen in the industry for a method of flexibly regulating communications between users on a calculator network.
In the present invention, a group of processing devices communicates by determining whether a processing device designated as a master device is a member of the group. If present, the processing devices determine whether the master device has allowed communication between other processing devices and initiates communication between devices either if the master device is not a member of the group or if the master device is a member of the group and has allowed communications between the processing devices.
The present invention provides significant advantages over the prior art. First, in settings where restrictions on communication are desired, the master processing device can allow or prohibit communications as desired. This is particularly useful in classroom settings. Second, in settings where communication should be unrestricted, the absence of a master device allows the processing devices to communicate freely. Thus, communication between processing devices may be restricted by the teacher in the classroom, without affecting communications outside of the classroom, such as in study groups.